European Design and Automation Association
Defect density and variabilities in values of parameters continue to grow with each new generation of nano-scale fabrication technology. In SRAMs, variabilities reduce yield and necessitate extensive interventions, such as the use of increasing numbers of spares to achieve acceptable yield. For most microprocessor chips, the number of SRAM bits is expected to grow 2x for every generation. Consequently, microprocessor chip yields will be seriously undermined if no defect-tolerance approach is used. In this paper, the authors show the limits of the traditional spares-based defect-tolerance approaches for SRAMs.